This invention relates to tracheal assemblies.
A patient may be ventilated and supplied with anaesthetic gas via an airway in the form of an endotracheal tube inserted via the mouth or nose, the patient end being located in the trachea just below the vocal chords. In other cases, a laryngeal mask airway may be used for ventilation, the patient end of this device terminating in the region of the pharynx. Alternatively, the patient may be ventilated by means of a tracheostomy tube, the patient end of which is inserted in the trachea via a surgically made opening in the patient's neck. Tracheostomy tubes are preferable for long term use because they do not provide any obstruction in the mouth and are better tolerated by the patient. In some cases, a patient may be ventilated initially using an endotracheal tube and then by a tracheostomy tube, when it becomes apparent that the patient will need prolonged ventilation. The surgical operation needed to introduce the tracheostomy tube involves cutting through the skin and tissue over the trachea in order to make the tracheostomy. One problem with this is that, if the cut is made too deep, it can cause damage to the posterior wall of the trachea. This risk is particularly great where a percutaneous or cricothyroid puncture tracheostomy is made.